1. Statement of the Technical Field
The present invention relates to delivering directory assistance services to a telephone subscriber, and more particularly to automatic call completion in a directory assistance system through a public switched telephone network (PSTN).
2. Description of the Related Art
The intelligent network of today bears little semblance to the PSTN of old. In fact, the term “intelligence” has little to do with the operation of the conventional PSTN. Rather, the conventional PSTN of old incorporates a massive complex of switching matrices and transport trunks that, through the electronic equivalent of “brute force”, forge the interconnections necessary to call completion. More particularly, for decades for every call processed the PSTN relied upon each successive switch to route a voice signal to the next. Still, the modern volume of calls processed within the conventional PSTN demands a faster, more streamlined approach to call routing.
To overcome the elements of the brute force aspect of the conventional PSTN, physically separate signaling networks have been grafted upon the transport and switching PSTN elements to oversee call set-up and billing. These “out-of-band” adjuncts speed routing data and commands directly to the switches involved, establishing all the necessary links prior to the actual transmission of a call. Consequently, with “out-of-band” signaling the PSTN has become “conscious” of the operations it is to perform prior to their execution. As a result, the PSTN has become a more flexible beast, capable even of substantial logic.
The development of the “out-of-band” protocol, Signaling System 7 (SS7), has led to the widespread deployment of intelligent network technology. In SS7, signaling links transmit routing packets between switches. Consequently, specialized SS7 Signaling Transfer Points (STPs) appeared to shepherd routing messages from local switches onto a high-capacity packet switches for distribution to other switches, STPs and call-related databases, such as the Line Information Database (LIDB), the Local Number Portability (LNP) database, the Toll Free Calling database and other databases containing additional call routing instructions. And, so, the agility of high-speed computer networking began exerting control over the raw power of the PSTN.
The marriage of convenience between SS7 and the PSTN soon produced the Advanced Intelligent Network (AIN)—an architecture where centralized databases control call processing. Logic ported via STPs to select switches now have become widely distributed throughout the network. AIN-capable switches also have begun to function as interactive signaling-platforms. Equipped with resident software triggers, AIN capable switches now can halt a call in progress long enough to query Service Control Points (SCPs)—databases containing service logic and subscriber information—which can provide instruction as to how to route, monitor, or terminate the call. The PSTN of today now effectively includes long-term memory as well as intelligence. Accordingly, the modern local exchange carrier holds the means to deploy such advanced telecommunications features such as telephone number portability, wireless roaming, call waiting and a host of other subscriber options.
The LIDB is a database configured for coupling to the PSTN through an SCP. The LIDB typically includes amorphous records arranged to store information regarding telephone callers, such as the name of the caller, the address of the caller, billing information for the caller, and the like. By storing invariable information regarding the caller, such as the name, address and billing method, many intelligent telephonic services can be provided over the PSTN through a simple query to the LIDB. In this regard, several local exchange carriers have deployed independent LIDB access services to facilitate the deployment of intelligent telephonic services which can exploit the invariant information stored within the LIDB.
Despite the wealth of information associated with a telephone caller stored in the LIDB, the LIDB seems to remain an untapped resource suitable only for advanced telephony billing applications. Accordingly, many conventional inconveniences remain prevalent in the world of the call center. For instance, in a directory assistance system, when a calling party requests a telephone number lookup, the directory assistance system can automatically connect the calling party to the selected phone number retrieved in consequence of the lookup operation. Notably, the call can be connected regardless of the telephone charges associated with the call, including long distance charges. In fact, typically, the calling party remains unaware of such charges and the calling party may decline the use of the automatic connection service without certain knowledge of the cost of the proposed telephone call.